A conventional continuously variable transmission, such as that disclosed in JPH8-178063A, in which a belt is looped around a primary pulley and a secondary pulley and a primary pulley pressure is controlled according to the operating position of a step motor, comprises storage means capable of storing a current operating position of the step motor, a speed ratio, and so on as pulley information. When a vehicle is activated, initialization of the step motor is performed on the basis of the stored pulley information, and after confirming the home position of the step motor, the step motor is displaced to an operating position corresponding to the stored speed ratio. Thus start control is performed from the speed ratio at the vehicle stopping time. The storage means typically comprise a backup power source so that the stored pulley information is retained even when the power source of the vehicle is OFF.
Further, when the primary pulley pressure does not rise to or above a predetermined pressure even after a predetermined period of time has elapsed following activation of the vehicle, control such as that disclosed in JP2004-125037A may be performed. In this control, it is determined that a deviation has occurred between the stored pulley information and the actual speed ratio, and while gradually displacing the step motor to an operating position corresponding to a High speed ratio, a determination is made as to whether or not the primary pulley pressure has increased. Thus, the vehicle can be started by setting the step motor to an appropriate operating position.